Calories Burned Calculator
Estimate how much energy a workout uses: choose the activity, enter your weight and duration, and the calculator applies the MET values published in the 2011 Compendium of Physical Activities. The table below shows what the total looks like in everyday food.
MET values are averages for able-bodied adults from the 2011 Compendium of Physical Activities (Ainsworth BE et al., Med Sci Sports Exerc 2011;43(8):1575-1581), with 1 MET counted as 1 kcal per kilogram per hour. The total is gross energy for the session — the extra above resting is about 1 MET less. Food values are typical serving averages from USDA data and vary by brand and portion, so read every figure as an approximation.
Formula and calculation
Worked example
A 70 kg person walking at a level 3.0 mph for 30 minutes burns 123 kcal: 3.5 METs × 70 kg × 0.5 hours. Kept up for a full hour the same walk would cost 245 kcal, and the chart below translates the session into bananas, pizza slices and other everyday food.
Why the number is only an estimate
A MET value is the average of what researchers measured while groups of people did the activity — it is not a measurement of you. Two people of the same weight can burn quite different amounts, because economy of movement, fitness and body composition all shift the cost, and effort inside one activity varies more than any table can capture (a flat walk and a hilly walk share a row here). There is also a definitional wrinkle: the oxygen-based version of the formula puts 1 MET at about 1.05 kcal per kilogram per hour, roughly 5% higher than the convention this page uses, which is why two calculators can disagree slightly on identical inputs. Treat the result as a ballpark with a margin of maybe a fifth either way, and use it to compare one activity with another rather than to balance a food diary.
What the results mean
- Calories burned
- Total energy for the whole session in kilocalories: MET value × your weight in kilograms × the hours you spent. This is gross energy — it includes what you would have burned at rest during that time.
- MET value
- The MET value of the activity, from the 2011 Compendium of Physical Activities. One MET is resting energy use, so 9.8 METs means running costs nearly ten times what sitting still costs.
- Per hour at this pace
- What the same activity would cost in a full hour at your weight — the MET value multiplied by your weight in kilograms. Handy for comparing two activities of different durations.
Frequently asked questions
How are calories burned calculated?
Calories = MET × weight in kilograms × hours. The MET value describes the activity: walking at a level 3.0 mph is 3.5 METs, so a 70 kg person walking for half an hour burns 3.5 × 70 × 0.5 = about 123 kcal. One MET is resting energy use, counted here as 1 kcal per kilogram per hour — the convention the Compendium's own kilocalorie equations are built on.
How accurate is this estimate?
It lands within perhaps 20 to 30 percent for most people, which is good enough to compare activities but not to balance a food diary. The MET values are group averages measured under laboratory conditions, and real sessions differ in effort, terrain and pace. If you need a precise figure, a heart-rate monitor with your own calibration or a lab test is more accurate.
Does the total include calories I would have burned anyway?
Yes — it is gross energy for the session, and it includes the resting metabolism you would have used sitting still. At rest you would still spend roughly 1 MET, so the extra that the exercise itself adds is about 1 MET less than the figure shown: for the walking example that is 2.5 METs rather than 3.5. Most calculators and machines report gross numbers, so comparisons stay fair as long as you use the same convention.
Should I eat back the calories I burned?
Not exactly, and it is not a useful goal. Appetite and hunger hormones respond to exercise in ways that vary a lot between people, and studies of weight change rarely match the arithmetic of burning and eating back. Exercise is valuable for fitness, strength, sleep and mood regardless of the calorie count, so use this number for planning energy needs and comparing workouts — not as an excuse for dessert.
Why do different calculators give different numbers for the same workout?
Three usual reasons: which MET table they use (the 2000 and 2011 Compendium editions differ for some activities, and some sites use older exercise tables), whether they report gross energy or net energy without resting metabolism, and whether they count a MET as 1 kcal per kg per hour or as the oxygen-based equivalent that is about 5% higher. Duration rounding and whether warm-up was included also move the total.